Packaging of fruit juices has been an ever-evolving field of research. From manufacturing to consumption of such packaged juices, the time period may typically extend to several weeks and months. Therefore, it becomes very important for manufacturers of such packaged juices, to retain the freshness, flavor, chemical and physical properties of such juices while packaging them and still increase the shelf lives of such packaged juices. The consumer on the other hand in his or her good right is naturally expecting the flavor profile to be as close as possible to the original, raw product and is often disappointed when it doesn't, which detrimentally affects sales and the popularity of such packaged juices.
Low acidic juices and/or liquids, such as coconut water, coconut milk, coconut oil, milk, apple juice, strawberry juice, pear juice etc., find more complexity when it comes to packaging them. Generally, such low acid liquids and/or juices while being packaged undergo numerous industrial processes, such as extraction, pasteurization, filtration, degazing, enzyme neutralization, additives, radiation etc., which eventually damage and/or alter the original organoleptic properties of such fluids.
One known way of packaging such low acid juices include treatment of such juices to increase their shelf lives. Examples of such treatments known, include heat treatment, Ultra High Temperature (UHT) treatment, pasteurization treatments, chemical and/or radiation treatment. However, each of these treatments exposes the liquids and/or juices to modifications of the original chemical and physical properties which may be unhealthy for consumption. For example, exposure of juices to UHT may modify the chemical profile of juices by creating caramelization of sugars. These treatments also modify the flavor profile of such juices, thereby making them less appealable or rather unappealing to the consumers.
Similarly, under radiation such as Ultra Violet treatment, the UV rays cannot achieve complete sterility if applied moderately and if applied intensively damages the flavor profile and/or molecular connections of the juice.
Further, with chemical treatment, such as acidification, the chemical profile, such as PH profile of the juice may be altered. Addition of additives to increase the shelf lives of such packaged low acid juices again detrimentally alter the chemical profiles and flavor profiles of the original raw juices.
The low acid juices may also be filtered using many conventionally known techniques, such as traditional micro filtration including ceramic filtration, absolute cartridge filter or crossflow filter. However, either these filtration systems do not ensure aseptic filtering of such juices, or if they do, these filtration systems detrimentally affect the flavor profile of the juices by removing aromatic compounds, phyto-elements, minerals and nutrients, making them less appealing to the consumers than their original raw counter-parts. Current commercially available micro-filtration systems that do not alter the organoleptic properties of juices are designed for laboratory or pharmaceutical use and therefore cannot keep up with the flux requirement needed in the industrial juice industry. These micro-filters clog rapidly after a short period of operation.
High Pressure Processing (HPP) has become increasingly used to treat fresh juices in the past years. The HPP technique however cannot eliminate the bacterial spores, which can lead to eventual development of pathogens when the packaged juice is exposed to temperature. The same applies for Pulsed Electric Field treatment.
A micro sieve filtration technique may be used for filtering such juices without altering the flavor profile and the nutrient content of the juices. However, while filtering, the s and/or the pores on such micro sieve membranes may get clogged by a layer of impurities, also called cake layer, which may result in degradation of the filtration capabilities of such filters.
Known methods of cleaning such clogged pores include back pulsing technology.
The back pulsing technology exposes the pores on the micro sieve membrane to pressure strokes from the filtrate side. Although the pressure strokes temporarily clear the spores, but it doesn't ensure complete removal of the cake layer from the membrane. Therefore, the pores get clogged again. High frequency back pulsing is therefore used to constantly push the cake layer up on the pores. As the cake layer becomes thicker and thicker during operation the flux drastically drops. Because of that and because the micro sieve is not cleaned over its entire surface during normal operation regular dismantling of filtration unit is necessary for some additional manual cleaning with chemicals directly applied on the micro sieve. The process is time consuming, even dangerous depending on the chemicals used and due to the fragility of the micro sieves themselves unpractical to perform in real life industrial settings. Additionally, the pressure strokes also tend to create vibrations that have been seen damaging or even shattering the very thin and delicate micro sieve membrane.
Therefore, there is a need for an improved system and a method for packaging low acid liquids under aseptic and sterile conditions.